This could come with the same concern. If a lot of these Windows 8 installs are new machines or clean installs there may not be as much third-party software installed so crashes that happen are more likely to occur in Windows components.

That said, the explorer crashes do worry me.

It's very sloppy, but not unusual for Microsoft, and easily fixed.

Could some of these be caused by 3rd party in-process shell extensions? Especially ones that aren't compatible with Windows 8?